Accessory device for EUS-FNA needle for guidewire passage

ABSTRACT

A combined system for diagnostic and therapeutic procedures includes a needle extending longitudinally from a proximal end to a distal end and including a lumen extending therethrough, the distal end including a sharp grind for cutting a tissue sample to be collected in the lumen of the needle and a protective sheath sized and shaped to be inserted through the lumen of the needle such that a distal end of the protective sheath extends distally past the distal end of the needle, the protective sheath extending longitudinally from a proximal end to the distal end and including a lumen extending therethrough.

PRIORITY CLAIM

The present application is a Continuation of U.S. patent applicationSer. No. 14/937,291 filed Nov. 10, 2015, now U.S. Pat. No. 10,149,665;which claims priority to U.S. Provisional Patent Application Ser. No.62/086,973 filed Dec. 3, 2014. The disclosures of the aboveapplication(s)/patent(s) are incorporated herewith by reference.

BACKGROUND

As therapeutic Endoscopic Ultrasound (EUS) procedures continue toadvance, it is important for a guidewire to safely pass through anEUS-FNA needle. Therapeutic EUS applications requiring guidewire passageinclude, for example, EUS-guided biliary, pseudocyst and gallbladderdrainage. In some cases, particularly when the EUS-FNA needle andguidewire are passed through a tortuous path, the guidewire insertedthrough a standard EUS-FNA needle may be sheared by the sharp grind ofthe needle during manipulation, compromising the ability to manipulatethe wire and/or exchange devices. This may result in a loss of access tothe target area and an increase in procedure time and cost. In addition,parts of the wire and coating may be left behind in the anatomyrequiring additional intervention and potential trauma to the patient.

SUMMARY

The present disclosure is directed to a combined system for diagnosticand therapeutic procedures, comprising a needle extending longitudinallyfrom a proximal end to a distal end and including a lumen extendingtherethrough, the distal end including a sharp grind for cutting atissue sample to be collected in the lumen of the needle and aprotective sheath sized and shaped to be inserted through the lumen ofthe needle such that a distal end of the protective sheath extendsdistally past the distal end of the needle, the protective sheathextending longitudinally

In an embodiment, the system may further comprise a guidewire extendingfrom a proximal end to a distal end and sized and shaped to be insertedthrough the lumen of the protective sheath.

In an embodiment, the needle may include an engaging element at theproximal end thereof.

In an embodiment, the protective sheath may include a correspondingengaging structure at the proximal end thereof engagable with theengaging element of the needle so that, when the protective sheath isinserted in the lumen of the needle, the engaging element and thecorresponding engaging structure engage one another to lock theprotective sheath relative to the needle.

In an embodiment, the engaging element may be a luer fitting.

In an embodiment, the system further comprises a stylet extending from aproximal end to a distal end and sized and shaped to be inserted throughthe lumen of the needle.

In an embodiment, the protective sheath may be formed of one of Nitinoland Cobalt Chromium.

In an embodiment, an outer diameter of the protective sheath may rangefrom between 0.030 inches (0.762 mm) and 0.035 inches (0.889 mm).

In an embodiment, an inner diameter of the protective sheath may rangefrom between 0.0265 inches (0.673 mm) and 0.030 inches (0.762 mm).

In an embodiment, the distal end of the protective sheath may bebeveled.

In an embodiment, the protective sheath may include a metal ring along adistal portion thereof which, when the protective sheath is inserted inthe lumen of the needle, is positioned within the distal end of theneedle.

The present disclosure is also directed to a device for treating tissue,comprising a protective sheath extending longitudinally from a proximalend to a distal end and including a lumen extending therethrough, theprotective sheath sized and shaped to be inserted through a lumen of aneedle such that when the distal end of the protective sheath extendsdistally beyond a distal end of the needle, a guidewire inserted throughthe lumen of the protective sheath is protected from a sharp tip of theneedle.

In an embodiment, the protective sheath may be formed of one of Nitinoland Cobalt Chrommium.

In an embodiment, the protective sheath includes a metal ring along adistal portion thereof which, when the protective sheath is inserted inthe lumen of the needle, is positioned within the distal end of theneedle.

In an embodiment, an outer diameter of the protective sheath may rangefrom between 0.030 inches (0.762 mm) and 0.035 inches (0.889 mm) and aninner diameter of the protective sheath may range from between 0.0265inches (0.673 mm) and 0.030 inches (0.762 mm).

The present disclosure is also directed to a method for treating tissue,comprising inserting a needle to a target site within a patient bodywith a stylet received within a lumen thereof, a distal end of thestylet extending distally past a distal end of the needle to preventtissue from being collected within the lumen of the needle duringinsertion, removing the stylet from the needle and inserting aprotective sheath through the lumen of the needle such that a distal endof the protective sheath extends distally past the distal end of theneedle, and inserting a guidewire through the lumen of the protectivesheath until a distal end of the guidewire is within the target site.

BRIEF DESCRIPTION

FIG. 1 shows a perspective view of a distal portion of a systemaccording to an exemplary embodiment of the present disclosure;

FIG. 2 shows an enlarged perspective view of the distal portion of thesystem of FIG. 1 ;

FIG. 3 shows a longitudinal cross-sectional view of a needle and styletof the system of FIG. 1 ; and

FIG. 4 shows a longitudinal side view of the needle of the system ofFIG. 1 .

DETAILED DESCRIPTION

The present disclosure may be further understood with reference to thefollowing description and the appended drawings, wherein like elementsare referred to with the same reference numerals. The present disclosureis directed to endoscopic devices and, in particular, devices for usewith EUS-FNA needles. Exemplary embodiments of the present disclosuredescribe a system comprising a protective sheath insertable through alumen of an EUS-FNA needle to act as a barrier between a sharp tip ofthe needle and a guidewire passed therethrough so that the needle may beconverted to a therapeutic device providing access to a target site. Itshould be noted that the terms “proximal” and “distal,” as used hereinare intended to refer to a direction toward (proximal) and away from(distal) a user of the device,

As shown in FIGS. 1-4 , a system 100 comprises a protective sheath 102insertable through a lumen 106 of a needle 104 to protect a guidewire108 passed therethrough from being sheared by a sharp tip 110 at adistal end 112 of the needle 104, which may be formed as, for example, asharp grind. In particular, the needle 104 may be an EUS-FNA needlevisible under ultrasound guidance and including the sharp tip 110 tofacilitate the penetration of target tissue (e.g., for tissue sampleacquisition) within a patient's body. It may also be desirable to inserta guidewire 108 through the needle 104, for example, during EUS-guideddrainage procedures such as EUS-guided biliary, pseudocyst and gallbladder drainage. Facilitating the use of the EUS-FNA needle for bothtissue sample acquisition and guide-wire assisted procedures such asdrainage renders the device more versatile and may simplify and shortenprocedures. For example, a guidewire may be required to provide passageof other devices such as cystatomes, balloons and/or stents during adrainage procedure. Insertion of a guidewire through a blunt catheter orhypotube rather than an EUS-FNA needle including a sharp grind toprevent shearing would require the use of a separate needle device fortissue acquisition. FNA needles are much more frequently used and theability to convert an FNA needle into a blunt access needle using theprotective sheath 102 is advantageous and efficient. Use of theprotective sheath 102 with the needle 104 improves patient safety indrainage applications. The system 100 may further comprise a stylet 124configured to be received within the lumen 106 of the needle 104 duringan initial insertion of the needle 104 to a target site within a patientbody. In use, the needle 104 and stylet 124 may be inserted to thetarget site with a distal end 126 of the stylet 124 extending distallyof the distal end 112 of the needle 104 to prevent non-targeted tissuefrom entering the lumen 106 during insertion of the needle 104 to thetarget site. When it is desired to insert a guide wire to a target siteadjacent to a distal end of the needle 104, the stylet 124 may beremoved and the protective sheath 102 may then be inserted through thelumen 106 so that a distal end 128 of the protective sheath 102 extendsdistally of the distal end 112 of the needle 104. The guidewire 108 maythen be passed through a lumen 130 of the protective sheath 102 to thetarget site so that other devices necessary for the drainage of thetarget site may be guided therealong as would be understood by thoseskilled in the art.

As shown in FIGS. 3-4 , the needle 104 may be a standard EUS-FNA needleextending longitudinally from a proximal end 114 to the distal end 112and defining the lumen 106 extending therethrough. An outer surface 116of the needle 104 may include echogenic enhancing features 118 such as,for example, one or more grooves extending along and/or about a distalportion 120 of the needle 104. The needle 104 may include an engagingelement 122 such as, for example, a luer fixture, at the proximal end114 to engage a corresponding fixture or structure at a proximal end ofthe stylet 124 and/or protective sheath 102, as will be described infurther detail below.

The stylet 124 may also extend longitudinally from a proximal end 132 tothe distal end 126 and include a corresponding engaging element 134 atthe proximal end 132 for engaging the engaging element 122 of the needle104. A length of the stylet 124 may be selected so that, when the stylet124 is inserted through the lumen 106 of the needle 104 and thecorresponding engaging element 134 engages the engaging element 122 ofthe needle 104, the distal end 126 of the stylet 124 extends slightlydistal of the distal end 112 of the needle 104.

The protective sheath 102 extends from a proximal end (not shown) to thedistal end 128 and defines a lumen 130 extending therethrough. Thedistal end 128 may be beveled, rounded or otherwise shaped to preventdamage to surrounding tissue as would be understood by those skilled inthe art. The protective sheath 102 is sized and shaped for insertionthrough the lumen 106 of the needle 104 and the lumen 130 of theprotective sheath 102 is sized and shaped to slidably receive theguidewire 108 therein. The protective sheath 102 is formed of a materialthat is sufficiently flexible to be inserted through the needle 104 evenwhen the needle 104 extends along a tortuous path (e.g. along a naturalbody lumen in the patient's body) while also having sufficient hardnessand column strength to prevent enable it to be pushed through the needle104 and to prevent shearing despite contact with the sharp tip 110.Furthermore, the material must be able to present these qualities in athin-walled design. For example, the protective sheath 102 may be formedof Nitinol, Cobalt Chromium or any other materials having the propertiesdescribed above. In one example, the protective sheath 102 may have anouter diameter configured to be passed through a 19 gauge needle, whichmay have an inner diameter of approximately 0.037 inches (0.940 mm) andhave an inner diameter sized to receive a 0.025 inch (0.635 mm) diameterguidewire. The protective sheath 102 may, for example, be formed ofNitinol and have a wall thickness of 0.005 inches (0.127 mm). In anexemplary embodiment, the protective sheath 102 may have an outerdiameter ranging from between 0.030 inches (0.762 mm) and 0.035 inches(0.889 mm) and an inner diameter ranging from between 0.0265 inches(0.673 mm) to 0.030 inches (0.762 mm). In another embodiment, theprotective sheath 102 may be reinforced along a portion of its length(e.g., a portion adjacent to a distal end thereof) which is likely tocome into contact with the sharp tip 110. For example, a distal portionof the sheath 102 may include a metal ring 125 stiffer than theremainder of the sheath 102 so that this portion would have increasedresistance to damage from contact with the sharp tip 110 when theprotective sheath 102 is extended distally out of the needle 104.

The protective sheath 102 may also include a handle having an engagingstructure at the proximal end thereof which, when the protective sheath102 is inserted through the lumen 106 of the needle 104, engages theengaging element 122 of the needle 102 to lock a position of theprotective sheath 102 relative to the needle 104. The engaging structure127 may be substantially similar to the corresponding engaging element134 of the stylet 124. The engaging structure may be, for example, aluer fixture. A length of the protective sheath 102 may be selected sothat, when the protective sheath 102 is inserted into the lumen 106 andthe engaging structure 127 engages the engaging element 122 of theneedle 104, the distal end 128 extends distally of the sharp tip 110 ofthe needle 104 to protect the guidewire 108 from shearing as it isinserted through the lumen of the protective sheath 102.

In use, the needle 104 is advanced through, for example, through anecho-endoscope and inserted to a target site within an extraluminal,adjacent structure identified under ultrasound with the stylet 124inserted through the lumen 106 thereof. As indicated above, the needle104 and the stylet 124 are configured to be inserted through eventortuous paths of the body to the target site. The engaging element 122of the needle 104 and the corresponding engaging element 134 of thestylet 124 are engaged with one another such that the distal end 126 ofthe stylet 124 extends just distally of the distal end 112 of the needle104 to prevent damage to the scope in tortuous anatomy. The stylet 124is drawn proximally relative to the needle 104 to expose the sharp tip110 so that the sharp tip 110 may puncture the target site, providingaccess thereto. Subsequent to puncture, the stylet 124 may be advanceddistally relative to the needle 104 to expel any undesired tissue frombeing collected within the lumen 106 of the needle 104. Once the targetsite has been reached, the corresponding engaging element 134 isdisengaged from the engaging element 122 of the needle 104 and thestylet 124 is removed therefrom. The protective sheath 102 is theninserted through the lumen 106 of the needle 104 until the distal end128 of the protective sheath 102 extends distally past the distal end112 of the needle 104. The engaging feature of the protective sheath 102may be engaged with the engaging element 122 of the needle 104 to lockthe protective sheath 102 in a desired position relative to the needle104.

The guidewire 108 is then inserted through the lumen 130 of theprotective sheath 102 to the target site. The guidewire 108 is advancedthrough the protective sheath 102 during a device exchange in which theneedle 104 and protective sheath 102 is removed to ensure that theguidewire 108 does not lose access to the target site as the needle 104is withdrawn from the body so that other devices necessary for the EUSapplication (e.g., cystatomes, balloons, stents) may be guided over theguide wire 108 to the target site. A distal end of the guidewire 108 maybe anchored in position in the target site so that other EUS devices maybe guided therealong to, for example, dilate the target site tofacilitate drainage thereof. Multiple devices may be exchanged over theguidewire 108, as necessary, to treat the target site. Once the targetsite has been treated, as desired, the devices and the guidewire 108 maybe removed from the target site. In cases in which a tissue acquisitionis desired, removing the protective sheath 102 from the lumen 106 of theneedle 104 and reinserting the stylet 124 thereinto returns the needle104 to its initial functionality as an FNA needle for tissueacquisition.

It will be apparent to those skilled in the art that variations can bemade in the structure and methodology of the present disclosure, withoutdeparting from the scope of the disclosure. Thus, it is intended thatthe present disclosure cover the modifications and variations of thisdisclosure provided that they come within the scope of the appendedclaims and their equivalents.

What is claimed is:
 1. A method for treating tissue, comprising:inserting a needle to a target site within a living body with a styletreceived within a lumen thereof, a distal end of the stylet extendingdistally to a distal end of the needle to prevent tissue from beingcollected within the lumen of the needle during insertion; after thedistal end of the needle is in a desired position adjacent to the targetsite, removing the stylet from the needle and inserting a protectivesheath through the lumen of the needle such that a distal end of theprotective sheath extends distally past the distal end of the needle;inserting a guidewire through the lumen of the protective sheath until adistal end of the guidewire is within the target site; and after thedistal end of the needle has reached the desired position and before thestylet is removed from the needle, advancing the stylet distally toexpel tissue from the lumen of the needle.
 2. The method of claim 1,further comprising removing the needle from the target site.
 3. Themethod of claim 2, further comprising guiding a dilation device over theguidewire to the target site to dilate the target site.
 4. The method ofclaim 3, further comprising draining the dilated target site of a fluid.5. The method of claim 1, further comprising, before the stylet isremoved from the needle, drawing the stylet proximally relative to theneedle so that a sharp tip at the distal end of the needle punctures thetarget site to provide access thereto.
 6. The method of claim 1, whereinthe needle includes an engaging element at a proximal end thereof. 7.The method of claim 1, further comprising engaging an engaging structureat a proximal end of the protective sheath with the engaging element ofthe needle locking the protective sheath relative to the needle when theprotective sheath is inserted into the lumen of the needle.
 8. Themethod of claim 6, wherein the stylet includes an engaging elementconfigured to engage a corresponding engaging element of the needle. 9.The method of claim 1, wherein the protective sheath is formed of one ofNitinol and Cobalt Chromium.
 10. A method for treating tissue,comprising: inserting a needle to a target site within a living bodywith a stylet received within a lumen thereof, a distal end of thestylet extending to a distal end of the needle to prevent non-targetedtissue from being collected within the lumen of the needle duringinsertion, the needle extending from a proximal end to a distal end andincluding a sharp grind for cutting a tissue sample to be collected inthe lumen of the needle; after the distal end of the needle is in adesired position adjacent to the target site, removing the stylet fromthe needle and inserting a protective sheath through the lumen of theneedle such that a distal end of the protective sheath extends distallypast the distal end of the needle, the protective sheath extendinglongitudinally from a proximal end to the distal end and including alumen extending therethrough, the distal end of the protective sheathbeing rounded to prevent damage to tissue; inserting a guidewire throughthe lumen of the protective sheath until a distal end of the guidewireis in a desired position relative to the target site; and after thedistal end of the needle has reached the desired position and before thestylet is removed from the needle, advancing the stylet distally toexpel non-targeted tissue from the lumen of the needle.
 11. The methodof claim 10, further comprising removing the needle from the targetsite.
 12. The method of claim 11, further comprising guiding a dilationdevice over the guidewire to the target site to dilate the target site.13. The method of claim 12, further comprising draining the dilatedtarget site of a fluid.
 14. The method of claim 10, further comprising,after the distal end of the needle is in the desired position adjacentto the target site position and before the stylet is removed from theneedle, drawing the stylet proximally relative to the needle to exposethe sharp grind at the distal end of the needle and puncturing tissue atthe target site to provide access thereto.
 15. The method of claim 10,wherein the needle includes an engaging element at a proximal endthereof.
 16. The method of claim 10, further comprising engaging anengaging structure at a proximal end of the protective sheath with theengaging element of the needle locking the protective sheath relative tothe needle when the protective sheath is inserted into the lumen of theneedle.
 17. The method of claim 15, wherein the stylet includes anengaging element configured to engage the engaging element of theneedle.
 18. The method of claim 10, wherein the protective sheath isformed of one of Nitinol and Cobalt Chromium.